An extra 1,200 troops have been deployed to work at the Olympic Games as the scale of the shortfall left by security company G4S becomes ever larger. The decision to call in more troops will heap further embarrassment on G4S, whose chief executive, Nick Buckles, has been fiercely admonished by the home affairs select committee because his company failed to train sufficient personnel for the games.

In his disclosure to the committee, Buckles revealed that he did not know how many staff would be ready for work when the games begin, or how many of those who have received training will actually turn up for their shifts.

Paul Deighton, chief executive of London 2012 organising committee Locog, told the Guardian that G4S’s failure to supply enough guards was “hugely disappointing” but insisted that the substitution of temporary private security guards by permanent soldiers would bring tangible benefits.